fix: improve hot api for production mode - error reporting and babel …

[theKashey]

• smaller production bundle for root/hot
• prod babel plugin improvements
• should solve Version 4.8.5 introduces a new console error on every file unit tested with jest #1252
• addresses Using module for hot cancels some webpack optimizations in prod #1080

[codecov-io]

Codecov Report

Merging #1260 into master will decrease coverage by 0.16%.
The diff coverage is 72.22%.

@@            Coverage Diff             @@
##           master    #1260      +/-   ##
==========================================
- Coverage   80.83%   80.66%   -0.17%     
==========================================
  Files          37       37              
  Lines        1273     1288      +15     
  Branches      329      332       +3     
==========================================
+ Hits         1029     1039      +10     
- Misses        191      196       +5     
  Partials       53       53

Impacted Files	Coverage Δ
src/babel.prod.js	93.18% <100%> (+0.87%)	⬆️
src/AppContainer.prod.js	50% <40%> (-50%)	⬇️
src/hot.prod.js	66.66% <66.66%> (-33.34%)	⬇️

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